Abstract Body

We have fabricated Zr, Hf, Sn and Ce co-doped GdBa₂Cu₃O_y (Gd123) thin films on LaAlO₃ (LAO) single crystal substrates by fluorine-free metal organic decomposition (FF-MOD) method. To improve J_C-B properties, it is widely known that BaMO₃ (BMO₃: M=Zr, Hf, Sn, etc.), which has the same crystal structure as Gd123, is introduced as artificial pinning centers. In general thin films mono-doped with a single element M to introduce one type of BMO₃ have been widely studied. We previously reported that J_C-B properties improved for Ce and Zr co-doped Gd123 thin films fabricated on LAO single crystal substrates by FF-MOD method for the first time. The film co-doped with Zr 1.0 mol% and Ce 1.0 mol% achieved the highest J_C of 4.13 MA/cm² at 0 T, and 0.347 MA/cm² at 1.0 T under 77.3 K, which were 1.10 and 1.35 times larger than those for Ce 2.0 mol% mono-doped film [1].

In this study, we have fabricated thin films with Hf and Sn as additional co-doping elements and investigated their superconducting properties. The film co-doped with Sn 1.0 mol% and Hf 1.0 mol% achieved J_C of 2.81 MA/cm² at 0 T, and 0.246 MA/cm² at 1.0 T under 77.3 K.

References

[1] R. Ishii, H. Masuda, K. Sato, R. Kita, O. Miura, “Enhancement of critical current densities by co-doping with Ce and Zr for Gd123 thin films fabricated by fluorine-free MOD method”, The 35th International Symposium on Superconductivity, November 2022